What does "cut the mustard" mean — and why is it funny?

informal

Meaning

To reach the required standard; to be good enough.

Where it comes from

An American phrase from around 1900. Its true source is unknown, with mustard possibly used as slang for the best or most exciting thing.

Why it is funny

The humor is that nobody cuts mustard — it is a soft paste. The phrase pairs a confident meaning with an action that makes no sense, and we use it briskly anyway without ever picturing the knife.

Used in a sentence

"He's friendly enough, but as a chef he just doesn't cut the mustard."